Excavator cooling system



Oct. 8, 1968 e. w. MORK EXCAVATOR COOLING SYSTEM 5 Sheets-Sheet 1 FiledJan. 20, 1967 INVE N TOR G EOR G E W. MORK ym AT TORN EY G. W. MORK Oct.8, 1968 EXCAVATOR COOLING SYSTEM 5 Sheets-Sheet 2 Filed Jan. 20, 1967 Km a MM m EE VG NR l O E G AT TORNEY Oct. 8, 1968 3, w, M 3,404,732

EXCA VATOR COOLING SY STEM Filed Jan. 20, 1967 5 Sheets-Sheet 5 INVENTORGEORGE W.MORK

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ATTORNEY United St te Pa e 10 v 1 $404,732, EXCAVATOR COOLING SYSTEMGeorge W. Mork, South'Milwaukee, Wis., as'signor to Bucyrus-ErieCompany, South Milwaukee, Wis., a corporation of Delaware Y Filed Jan.20, 1967, Ser. No. 610,677

4 Claims. (Cl. 165-51) ABSTRACT OF THE DISCLOSURE An hydraulic excavatorpowered by a liquid cooled diesel is described. The diesel and theprincipal hydraulic components are sealed in a housing except for twoair inlet ports on opposite sides near the front and an outlet port inthe back. The diesel is mounted in the back with the hydrauliccomponents in front of it, so that air drawn by the fan of the dieselcools the hydraulic components.

Background of the invention in hydraulic excavators and cranes, greatquantities of heat are generated in thehydraulicsystem and absorbed inthe hydraulic fluid. If the heat generated in the hydraulic system isnot dissipated, it will increase the temperature of the oil to beyondits breakdown point, and it could be damaging to the hydrauliccomponents of the system. Therefore, it has been customaryin the past toprovide large heat exchangers for cooling the hydraulic fluid, and toopen the machinery housing of the excavator during use so as to exposethe hydraulic equipment as much as possible to the ambient air. The heatexchangers required to provide the necessary cooling are very expensive.Moreover, they occupy precious space in the machinery housing of theexcavator, and they add substantially to the weight and powerrequirements of the hydraulic system. The present invention'has, in manycases,obviated the need for additional heat exchangers for the hydraulicequipment altogether, and in others it has greatly reduced the size andcost of the heat exchangers required. Generally speaking, this isaccomplished by employing the air flow generated for the radiator of theprime mover engine to cool. the hydraulic apparatus; While thisinvention requires .an increase in the capacity of the cooling system ofthe engine, due to the elevated temperature of the air coming from thehydraulicequipment, this addition is miniscule when compared with theamount of otherwise needed cooling equipment for the hydraulic fluidthat has been eliminated.

The prior art directly related to the invention, as was mentioned above,involvesthe, use of special heat exchangers and simple exposure of thehydraulic equipment. Structure superficially similar .to the presentinvention evolved out of the necessity to cool the engines in sealedmilitary vehicles such as amphibians, U.S. Patents Nos. 2,341,165 and"2,416,128, and" military tanks, U.S. Patents Nos. 2.,"853g153'and2,435,513f, as well "as in engine cowling for aradial engine, U.S.Patent'No. 1,925,415; The invenlions bf 'the cited p'atents relating tothe miliary vehicles all provide solutions to the problem of getting airto the =radiatrof an enginefwhic'h must befsealed against damagefromits;environmerrtg'Theieiigineof atank must be seur'd against" nemyfire and'the engine of an amphibian must be secured against waterleakage, and the problem 3,404,732 Patented Oct. 8, 1968 arises becausethe engine cannot be exposed to the air through which the vehicle ismoving, as is taught in Patent No. 1,925,415 cited above, and as isemployed generally in motor vehicles. But the teachings of those patentsdo not respond to the needs met by the present invention.

Summary of the invention The present invention, therefore, relates to acooling system for hydraulic fluid in an hydraulic excavatorand, morespecifically, the invention resides in the combination in an excavatorhaving a completely enclosed machinery housing containing an engine witha radiator and a :fan and at least part of an hydraulic power unit foroperating the hydraulic excavator mounted in the machinery housing andaligned between an air inlet port and anair outlet port formed in thewalls of the machinery housing-so that the air drawn through the housingby the engine fan will cool said part of the hydraulic power unit.

Brief description of the drawings FIG. 3 is a rear elevation of the backhoe shown in FIGS. 1 and 2.

. FIG. 4 is a side elevation of the back hoe shown in FIGS. 1 through 3from the opposite side of that shown in FIG. 2 with most of the boombroken away.

Description of the preferred embodiment Referring initially to FIG. 2and FIG. 4, a back hoe type of excavator 1 having a revolving frame 2which is rotatably mounted on crawler type running gear 3 for propulsionis shown. The revolving frame 2 supports a counter weight 4 on its backend 5, and a boom pedestal 6 with a boom 7 pivotally mounted thereon onits front end 8. To control the elevation of boom 7 a pair of hydraulichoist cylinders 9 are also shown, although the remainder of the boom 7with its excavating implement and other gear has been omitted to allowmaximum enlargement of the portion of the excavator relating directly tothe invention. Of course, many forms of boom 7 with associated hydraulicequipment and implements are well known to the art, so disclosure of anyspecific boom structu're may be omitted here since that specificstructure is not pertinent to this invention. Moreover, it should alsobe noted herethat the invention is not limited to back hoes, and theterm excavator when used to describe or claim this invention is intendedalso to include cranes.

The revolving frame 2 supports a machinery housing 10 which iscompletely enclosed by side walls 11 and 12,

is fitted with a protective grill 17. In each of the side walls II and'12, toward the front end of the machinery housing 10, air inlet ports18 and 19 are formed, and these also are fitted with protective grills20 and 21, respectively. Since the air outlet port 16 must be locatedabove the counter weight 4, it is close to the roof 15 of the machineryhousing 10, whereas the air inlet ports 18 and 19 are located-just abovethe floor 22 on the revolving frame 2 at the front lower corners of theside walls 11 and 12, and hence they are at a lower level than theoutlet port 16. An enclosed operators cab 23 is mounted on the righthand side of the revolving frame 2 immediately in front of the machineryhousing 10.

FIG. 1 illustrates the layout of the machinery and equipment on therevolving frame 2. A liquid-cooled, V-6 diesel engine 24 is mounted onthe center of the revolving frame 2 toward its back end 5. Between thediesel engine 24 and the air outlet port 16, which is directly alignedwith and just behind the diesel engine 24, is a radiator 25 for thecooling liquid for the diesel engine 24. Between the radiator 25 and thediesel engine 24 is fan 26, which is driven by the diesel engine 24 forpropelling cooling air through the radiator 25. On each side of thediesel engine 24, tanks 27 are mounted on the revolving frame 2 forstoring hydraulic fluid and fuel oil. Also, certain other auxiliaryequipment 28 is mounted next to the diesel engine 24 on the revolvingframe 2. A pair of hydraulic pumps 29 and 30 are mounted on the frontend of a transmission 31, which in turn is mounted on the front end ofthe diesel engine 24 for transmitting driving power from the dieselengine 24 to the pumps 29 and 30. In front of the tanks 27 on the righthand side of the machinery housing 10 are mounted a pair of hydraulicvalves 32 and 33, and another bydraulic valve 34 is mounted just left ofcenter on the revolving frame 2 in front of the diesel engine 24. Thehydraulic valves 32, 33 and 34 are the principal valves of the hydraulicpower unit and these control the propulsion and swing as well as theother excavating operations. A pair of hydraulic motors 35 and 36 arealso mounted on the revolving frame 2 in the machinery housing 10 infront of the diesel engine 24 with its hydraulic pumps 29 and 30. As isappreciated by anyone who has ever seen an hydraulic excavator, thehydraulic pumps 29 and 30 are inter-connected with the hydraulic valves32, 33 and 34 and the hydraulic motors 35 and 36 by numerous, largecapacity, high pressure hydraulic conduits, which are omitted here fromthe drawings in order to avoid presenting a confused tangle of linesthat would only obfuscate the disclosure. However, this vast footage ofconduit also contains a great deal of oil which is cooled in the samemanner as the oil in the components 29, 30, 3236 shown here. Thesehydraulic components and the associated conduits constitute the mainpart of the hydraulic power unit for driving the excavator. Thehydraulic valves 32 through 34 are connected to controls in theoperators cab 23 by means of mechanical linkages 37, some of which arerepresented here and some of which are not.

Whenever the excavator 1 is operating, the diesel engine 24 is runningand driving the fan 26. The fan 26 will draw air through the inlet ports18 and 19, as indicated by the small arrows in the drawings, and overthe portion of the hydraulic power unit including the components 29-36shown here. The air passing over the hydraulic components 29-36 andconduits will serve to cool them, and thus the hydraulic fluid in themto maintain the hydraulic fluid within its prescribed temperature range.Of course, the air, receiving heat from the hydraulic power unit, willbe unable to cool the liquid in the radiator 25 of the diesel asefiiciently as otherwise. Hence, the cooling capacity of the radiator25, or the capacity of the fan 26, or both, should be increasedcommensurately.

In the past it has been customary to open the sides of the machineryhousing 10 whenever the excavator 1 was in operation to allow formaximum cooling'of the diesel engine 24 and any other equipment in themachinery housing 10. Hereafter, with the application of the presentinvention it will be imperative to keep the machinery housing 10completely closed except for the air ports 16, 18 and 19 so as topreserye the controlled air flow through the air duct created by themachinery housing 10. Of course, in the past it has also been necessaryto employ large and expensive heat exchangers with separate fans forcooling the hydraulic fluid, but in embodiments such as the onedescribed here, such heat exchangers may be omitted entirely and inother embodiments the size and cost of the heat exchangers stillrequired may be drastically reduced. Not only is the overall efiiciencyof the excavator substantially increased, but the sealing of the,machinery housing 10 also permits filtration of the cooling air andcleanliness around the machinery and equipment and sharply reducedoperating noise level. The isolation of the operator from the noise anddistraction of the machinery both improves working conditions andrenders the use of such equipment safer. All of these objects andadvantages may be obtained through the invention set forth in thefollowing claims.

I claim:

1. A cooling system for hydraulic fluid in combination with a hydraulicexcavator comprising a revolving frame for supporting powered machineryfor driving said hydraulic excavator;

an enclosed operators cab for housing an operator and controls;

a machinery housing separate and isolated from said operators cab,mounted on said revolving frame and being completely enclosed by wallsincluding side Walls, a front end wall, a back end wall a floor, and aroof;

an air outlet port through one of said walls of said machinery housing;

at least one air inlet port through another of said wall of saidmachinery housing;

said walls of said machinery housing along with said air inlet port andsaid air outlet port forming an air duct through said machinery housing;

an engine mounted inside said air duct in said housing and having aradiator adjacent said air outlet duct and a fan mounted to draw airthrough said air inlet duct over said engine and forcing said airthrough said radiator and out said air outlet duct;

and at least part of a hydraulic power unit for driving said hydraulicexcavator being mounted in said air duct in said housing between saidengine and said inlet port.

2. A cooling system for hydraulic fluid in combination with a hydraulicexcavator as set forth in claim 1 wherein said engine is mounted nearsaid back end wall of said machinery housing and substantially centeredin said machinery housing;

fuel and hydraulic fluid tanks and other auxiliary equipment are mountedbetween said side walls of said machinery housing and said engine;

said air outlet port is located in said back end wall of said machineryhousing;

and said radiator is mounted adjacent said air outlet port with said fanmounted between said engine and said radiator. v v

3. A cooling system for hydraulic fluid in combination with a hydraulicexcavator as set forth in claim 2 wherein said part of said hydraulicpower unit is mounted in front of said engine and on a lowerleve1than,said

engine; and air inlet ports are, formed in opposite side walls of saidmachinery housing adjacent to said hydraulic power unit and at a lowerlevel than said air outlet 75 port. I

5 6 4. A cooling system for hydraulic fluid in combina- References Citedtion with a hydraulic excavator as set forth in claim 1 UNITED STATESPATENTS wherein 2,341,165 2/1944 Todd 123-4149 x said frame is arevolving frame supported for propul- 2 41 12 2 1947 Swennes 23 41 49 Xsion on crawler type running gear; 5 2,423,929 7/1947 Dilworth et a1.12341.49 X said operators cab is mounted on said revolving frame 1 132/1948 Rogers et 12341-49 X in front of said machinery housing; FOREIGNPATENTS and said part of said hydraulic power unit includes 519,7471/1921 France.

hydraulic pumps driven by said engine and principal 10 718,135 11/ 1954Great Britain. control valve units with associated manifolds and ROBERTA. OLEARY, Primary Examiner. piping for hydraulic fiuid. A. W. DAVIS,Assistant Examiner.

